BLOCK ISLAND, RI — Remember that one thing you’d never make it to the driveway without?

Your keys. Now there are two things. It’s tough to imagine a day without that everything-in-your-pocket thing we used to call “a cell phone.”

Texting and Twitter have raised the bar on Email.

When I first started consulting, client stations would mail me aircheck cassettes in padded envelopes. No, Harry Truman was not in the White House. That was first-term Clinton administration era technology. Tick tock.

Back to the future: As life got faster, short attention begat short-format messaging; and now email’s place in the communication tool box is for attaching documents or sending messages which themselves are documents.

With enabling technology evolving so rapidly, technique is critical. With new-tech comes a new etiquette; or, too often, a lack thereof. You prove it every time you check your email. I’ll bet you delete without reading more messages than you read.

The Subject line is the email “envelope,” the most important line of the entire message.

When your snailmail arrives today, you’ll sift through it over the wastebasket. In just a glance, at the outside of the envelope, we decide whether to bother opening the envelope.

Ditto subject lines, which provoke snap judgments.

One technique I’ve found useful: Make the first word the recipient’s name, and the next few words JUST-enough-of-what-the-message-will-convey to make the recipient curious. “Heidi: Just made plans to be there next week. Lunch?”

Got several issues? Send several emails.

Got three topics to broach with an associate? Send three separate single-topic emails.

Why:

Your associate might want to bring someone else into the loop on topic A, but not topics B and C. Emailing only about topic A spares the recipient the need to cut-and-paste…or, potentially, the embarrassment of not doing so.

The recipient might be reading a mobile device and not scrolling past Topic A.

When in doubt, don’t.

Email is easy, instant, and free, and that can be real embarrassing.

Email lacks the eye contact and body language you get in face-to-face conversation. Or the tone of voice and other nuance you hear in a telephone conversation. Email is just words…often few words. We’re all smothering in spam, so we often reply in terse fashion that’s easy to misunderstand.

Email doesn’t cost you a postage stamp, and lacks the deliberation time that’s built into a walk to the snailmail box. So it’s easy to succumb to the “Oh YEAH???” stimulus-response trap.

Unless you’re emailing AOL-to-AOL (rarer lately), there’s no Unsend.

Never send a follow-up email asking “Did you get my Email?”

If it didn’t bounce back undeliverable, it got where you sent it.

Also avoid trans-media pestering, i.e., calling-to ask “Did you get my email?” Or emailing to say, “I left you a voicemail.” When tough staffing choices are being made, pests are the first to go.

Puh-LEEZ: Don’t “Reply-to-All” when you can simply…Reply.

Occasional emailers unintentionally torture those of us who work online (and feel like we live there), by replying to the entire list to whom the message was sent.

Example: I was recently among 100-plus invited to a corporate reunion, always a warm affair. And that’s the problem. Enthusiasm for our upcoming get-together caused (too) many recipients to RSVP the organizer with a cheery reply to all, i.e., “I can’t wait!”

Then, others piled on with a reply to all to THAT! And THEN, the “I’m out of my office now” auto-responders joined in.

When I begged the reunion organizer to ask — in his next alert to all funsters — that we be careful to reply, rather than reply to all, he didn’t know that these were separate options. Hey, he’s retired. This — and family messages and photos and other reply to all stuff — are probably the only email he does.

So I did a reply to all, explaining the situation. Swearing that “I’m not a party-pooper…honest,” and promising that “I’ll be there, wearing the lampshade,” I asked that, in the interest of spam control, we all reply only to the organizer. And that, by doing so, we’ll help him avoid RSVP confusion.

Hey, at least I tried. One invitee, apparently also retired, shot back: “point taken, but the truth is, I really like seeing the responses, especially since they are coming so rapidly and are so positive,” with a smiley face.